Study on Performance of Electrocatalytic Dechlorination of 2, 5- dichloronitrobenzene by Copper and Palladium Bimetallic Composites Modified Ti Electrode in Aqueous Solution

摘要

In our work, a facile copper and palladium composites modified Ti electrode (Cu-Pd/Ti) was preparedby electrochemical deposition and chemical replacement method, which was applied for electrocatalyticdechlorination of 2, 5-Dichloronitrobenzene (2, 5-DCNB), a typical organic chloride pollutant. Themorphologies and structures of Cu-Pd/Ti were characterized by scanning electron microscopy (SEM),X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The electrochemicalperformance was examined by cyclic voltammetry (CV) and linear sweep voltammetry (LSV). Theexperimental results displayed that Cu polyhedrons were formed at the Ti electrode surface (Cu/Ti) andthe palladium metals were mainly coated at Cu/Ti electrode in the zero-valent and divalent states.Meanwhile, the copper-palladium composites were uniformly dispersed at the Ti electrode surface. Theelectrochemical experiments verified that Cu-Pd/Ti composite electrode exhibited high catalyticdechlorination property and large electrochemical active surface area (EASA) owning to the cooperativeinteraction of Cu and Pd composites materials. The Cu-Pd/Ti displayed better electrocatalytic efficiencytowards 2, 5-DCNB reduction than that of the other electrodes in this experiment. With a current densityof 2.25 mA/cm2, the electro-reductive removal rate of 2-DCNB reached 97.1% within 3 hours. Theintermediates and mechanisms of dechlorination were identified through high-performance liquidchromatography (HPLC) and gas chromatography coupled with mass spectrometry (GC-MS), and themain final products were properly transformed to aniline. This work may provide a beneficial choice forthe effective treatment of DCNBs in the environment..